Ventilating fan for picture projecting apparatus



y 1951 c. J. CADWELL ET AL 2,562,600

VENTILATING FANS FOR PICTURE PROJECTING APPARATUS Filed D80. 17, 1948 IN VEN TORS 6207291212 ll Cadwell fianlz'ljffl'da'morz Patented July 31,1951 UNITED STATES PATENT OFFICE VENTILATING FAN FOR PICTURE PROJECTINGAPPARATUS Application December 17, 1948, Serial No. 65,897

3 Claims. 1 I

The invention relates to a fan for picture projecting apparatus and itis an object of the invention to provide a device of this kind wherebythe heat generated by the lamp within the lamp housing in the shell ofthe machine is quickly dispersed to maintain the machine cool throughoutthe period it is in operation.

It is also an object of the invention to provide a means for dispersingthe heat generated within the apparatus whereby it is possible to safelyuse a lamp or bulb of high wattage.

Furthermore, it is an object of the invention to provide a fan forposition exteriorly of the shell of the projecting machine to draw outfrom the shell and disperse exteriorly thereof the air heated within theshell or more particularly the lamp housing within the shell.

The invention consists in the details of construction and in thecombination and arrangement of the several parts of our improved fan forpicture projecting apparatus, whereby certain advantages are attained,as will be hereinafter more fully set forth.

In order that our invention may be better understood, we will nowproceed to describe the same with reference to the accompanyingdrawings, wherein:

Figure 1 is a fragmentary view in section with parts in elevationillustrating a fan embodying the invention in applied position; and

Figure 2 is a fragmentary view in top plan of Figure 1 with a portionbroken away.

As illustrated in the accompanying drawings S denotes the shell oroutside casing of a picture projecting machine of a general type as usedin connection with still or moving pictures. Positioned in the shell orcasing S is a lamp H of a conventional type in which is placed the usuallight B. The top wall I of the shell or casing s is provided with thelouvered vents 2 directly along the lamp housing for the escape of theheated air within the shell or casing S.

The vents l themselves, however, do not allow for the escape of air insufiicient volume to maintain cooling of the walls 2 of the shell orcasing S or to permit the use of a bulb of high wattage. Thesedisadvantages are overcome by drawing out the heated air within thehousing in a manner whereby the walls of the shell or housing S aremaintained cool and a bulb or lamp of high wattage may be used withsafety especially with respect to the film or slides being used.

A relatively short sleeve 3 is positioned on the top wall I of the shellor casing S and surrounding the vents 2. In the present embodiment 2 ofthe invention the collar 3 is detachably held as at 4 to the top wall 1so that the same may be applied or removed as desired.

Extending inwardly from the outer or upper end portion of the sleeve 3are the diametrically opposed arms 5. These arms 5 are substantially inalinement and are secured, as at 6, by screw or the like, to bracket 1carried by the field ring a of the motor M. These arms 5 not onlysupport the motor M in desired position but provide means to hold thefield ring or against rotation.

The shaft 8 of the motor M is upwardly disposed and has fixed to itsupper extremity the axial center of the top head 9 of the fan F. Thisfan F comprises a cylindrical wall [0 depending from the peripheralportion of the head 9 and open at its bottom or lower end. The wallmember I0 is substantially housing the motor M.

The cylindrical wall [0 has struck therefrom and extending fromsubstantially one end to the other the blades I l providing air slots [2between each pair of blades ll. These blades H are equidistantly spacedand are arranged entirely around the wall In. The blades II are also onsuch pitch to provide means for creating such suction within the shellor housing S to withdraw therefrom and disperse out into the atmospherethe heated air with the shell or casing S and in such volume to assurethe maintenance of the shell or casing S substantially free of heat.

At predetermined spaced points therearound the upper or outer endportion of the collar 3, are the outwardly disposed ears l4 to which aresecured the upstanding posts l5 which extend upwardly into a dome D andhave close contact within the lower free marginal portion of the sidewall 16 of the dome D. The wall It; may be secured to the posts Is inany desired manner, as by screws H.

The side wall l6 and the top wall [8 of the dome D is imperforate andthe lower or open end of the dome is of a diameter to extend a distancematerially outwardly from the collar 3 whereby a discharge opening isprovided surrounding the collar 3 and through which is discharged theair after being drawn out from within the shell or casing S.

We claim:

1. In combination, a picture projecting machine including a casinghaving an exhaust opening through a wall thereof, a sleeve mounted onsaid wall exteriorly of the casing and surrounding the dischargeopening, a downwardly facing hood carried by the sleeve and positionedthereabove, said hood having its lower face open and of a diametergreater than the diameter of the sleeve, a shaft disposed axially of thesleeve and supported thereby, said shaft being of a length to extend adistance within the hood, means for rotating the shaft, a head carriedby the outer end portion of the shaft, and a wall extending from theperipheral portion of the head toward the sleeve, said wall havingblades struck therefrom and providing openings between adjacent blades.

2. In combination, a picture projecting machine including a casinghaving an exhaust opening through a wall thereof, a sleeve mounted onsaid wall exteriorly of the casing and surrounding the dischargeopening, a downwardly facing hood carried by the sleeve and positionedthereabove,

said hood having its lower face open and of a diameter greater than thediameter of the sleeve, a shaft disposed axially of the sleeve andsupported thereby, said shaft being of a length to extend a distancewithin the hood, means for rotating the shaft, a head carried by theouter end portion of the shaft, and a wall extending from the peripheralportion of the head toward the sleeve, said wall having blades strucktherefrom and providing openings between adjacent blades, said wallbeing of substantially the same diameter as the sleeve and terminatingclosely adjacent thereto.

3. In combination, a picture projecting machine including a casinghaving an exhaust opening through a wall thereof, a sleeve mounted onsaid wall exteriorly of the casing and surrounding the dischargeopening, a hood carried by and concentric with the sleeve, and said hoodhaving a circular open side spaced from and directed toward said wall,said circular open side being of a diameter greater than the diameter ofthe sleeve, a motor unit having a field ring and an armature therein,means supporting the motor unit in the center of the outer end of thesleeve with the turning axis of the armature concentric with the sleeve,a shaft supporting the armature and having an end extending outwardlyinto the hood, and a suction fan carried upon the outer end of the shaftwithin the hood, said suction fan comprising a cylindrical body having ahead and a wall extending from the head toward the sleeve, said wallhaving blades struck therefrom providing openings between the blades,and said motor being encircled by the wall and partially disposed withinthe fan body.

CLARENCE J. CADWELL.

FRANK M. ADAMSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,409,199 Roth Mar. 14, 19221,598,444 Howell Aug. 31, 1926 1,937,379 Berg Nov. 28, 1933 2,027,679Debrie Jan. 14, 1936 2,027,680 Debrie Jan. 14, 1936 2,126,230 TroxellAug. 9, 1938 2,153,576 Kurth et al Apr..11, 1939 2,165,681 StechbartJuly 11, 1939 2,186,618 Philips Jan. 9, 1940 2,269,794 Stechbart Jan.18, 1942 2,288,345 DeVry June 30, 1942

